In many wireless networks using channels in the 60 GHz range, line of sight signal paths are the predominant signal paths because the signals, especially reflected signals, are severely attenuated. This makes such networks well-suited for efficient spatial reuse, and are therefore good candidates for multi-user multiple input multiple output (MU MIMO) communications. In such networks, beam forming is important to create the highly directional channels needed for spatial reuse. Conventional methods of channel training are not well-suited for creating multiple spatial channels.